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Altitudinal Zones (altitudinal + zone)
Selected AbstractsWhite pines, Ribes, and blister rust: integration and actionFOREST PATHOLOGY, Issue 3-4 2010R. S. Hunt Summary The preceding articles in this series review the history, biology and management of white pine blister rust in North America, Europe and eastern Asia. In this integration, we connect and discuss seven recurring themes important for understanding and managing epidemics of Cronartium ribicola in the white pines (five-needle pines in subgenus Strobus). Information and action priorities for research and management of the pathogen, telial and aecial hosts, and their interactions are listed in a detailed Appendix. Syntheses focused on genetics, plant disease, invasive species or forest management have provided alternative but knowledgeable lessons on the white pine blister rust pathosystem. Two critical issues for the conservation of white pines are to sustain ecosystems affected by blister rust and to maintain genetic diversity for adaptive traits such as disease resistance. Forest genetics includes tree improvement and molecular techniques for research; their application can increase rust resistance by artificial and natural selection. Silviculture augments genetics with methods to deploy and enhance resistance as well as to regenerate and tend white pine stands. Although cultivated or wild Ribes might serve as inoculum sources, silviculture and horticulture can reduce the risk of serious impacts from blister rust using genetics for breeding and epidemiology for hazard assessment and disease control. Climate change threatens to cause major alterations in temperature and precipitation regimes, resulting in maladapted conifers succumbing to various diseases and insect outbreaks. In contrast, many white pine species have broad ecological ranges and are tolerant of harsh environments,traits that permit successful establishment and growth over wide geographic and altitudinal zones. Given appropriate management, white pines could thrive as valuable commercial and ecologically important keystone species. In an uncertain environment, adaptive management provides a learning and participatory approach for sustaining resilient ecosystems. [source] Karakorum,Hindukush,western Himalaya: assessing high-altitude water resourcesHYDROLOGICAL PROCESSES, Issue 12 2005M. Winiger Abstract The high mountains of Central and South Asia provide irrigation water for their adjacent lowlands. The Indus Irrigation Scheme depends on approximately 50% of its runoff originating from snowmelt and glacier melt from the eastern Hindukush, Karakorum and western Himalaya. The Atlas of Pakistan indicates that these mountains gain a total annual rainfall of between 200 and 500 mm, amounts that are generally derived from valley-based stations and not representative for elevated zones. High-altitude snowfall seems to be neglected and is obviously still rather unknown. Estimates derived from accumulation pits runoff above 4000 m range from 1000 mm to more than 3000 mm, depending on the site and time of investigation, as well as on the method applied. To assess the vertical spatio-temporal distribution of total annual precipitation, a combined approach is presented. This approach links in situ measurements of snow depth and water equivalent (10-year time series derived from automatic weather stations at elevations between 1500 and 4700 m a.s.l.), the spatial distribution and period of snow coverage (remotely sensed data and digital elevation models), and the runoff characteristics of streams originating from snow or snow/ice-covered watersheds (modified snowmelt runoff model, including intermediate snowfall and glacier runoff). Based on conservative assumptions, the vertically changing seasonal ratio between liquid and solid precipitation is calculated. Using a combined snow cover and ablation model, total annual amounts of precipitation are derived for different altitudinal zones. Amounts of modelled and measured runoff complement the investigation. Horizontal gradients along the Indus,Gilgit,Hunza transect indicate the varying dominance of seasonal precipitation regimes (monsoonal, Mediterranean and continental disturbances) south of Nanga Parbat, between Nanga Parbat and Batura Wall (=West Karakorum rainfall regime: 1500,1800 mm year,1 at 5000 m) and areas north of Batura (=Central Asian rainfall regime: ,600 mm year,1 at 5000 m). Copyright © 2005 John Wiley & Sons, Ltd. [source] Contrasting phylogeographical patterns of two closely related species, Machilus thunbergii and Machilus kusanoi (Lauraceae), in TaiwanJOURNAL OF BIOGEOGRAPHY, Issue 5 2006Su-Hwa Wu Abstract Aim, The purpose of this paper was to study the patterns of genetic variation, demographic history, haplotype relationships and potential location of diversity centres of two closely related species, Machilus thunbergii and Machilus kusanoi. Location, The phylogeography of M. thunbergii and M. kusanoi was examined by sampling 110 and 106 individuals from 25 and 16 sampling sites, respectively, across their distributional range in Taiwan. Machilus thunbergii is distributed on the Asian mainland, South Korea, southern Japan, the Ryukyus, Taiwan and the Philippines, whereas M. kusanoi is endemic to Taiwan. These two species are closely related, and both are widely distributed in Taiwan but occupy different altitudinal zones and habitats. Methods, The range-wide variation of M. thunbergii and M. kusanoi in Taiwan was studied using chloroplast DNA (cpDNA) variations. A haplotype network was constructed with the computer program tcs. Nested clade analysis was conducted with the computer program ceodis, and various parameters of genetic diversity were calculated and neutrality tested by the computer program DnaSP. Population differentiation was estimated using the programs arlequin and hapstep. The contribution of the populations to gene diversity and to allelic richness was calculated using the software contrib. The level of divergence for each population from the remaining populations was calculated as the mean value of pairwise FST for each population against the rest of the populations. Results, Extremely low levels of genetic differentiation were found for both species. This result suggested that these two species probably survived in multiple relict refugia with different population sizes throughout the island during low-temperature periods of the Pleistocene. In addition, nested clade analysis (NCA) of cpDNA haplotypes indicated that restricted gene flow with isolation-by-distance characterized the recolonization after the Pleistocene by Tashueshan and Shiouhluan populations of M. thunbergii in the north-central area west of the Central Mountain Range (CMR). In contrast, NCA analysis indicated that a major diversity centre on the southern tip of the island (Kending population) and contiguous range expansion characterized the recolonization by M. kusanoi of northern areas along the east side of the CMR. The major diversity centres found for the two species examined were further supported by the results of the mean FST for individual populations in comparison with other populations, and of the contribution of the divergence component to the total diversity. Main conclusions, This research supports the multiple relict refugia hypothesis for both species investigated. Populations of M. thunbergii at Shiouhluan and Tashueshan in the north-central area west of the CMR represent a diversity centre currently expanding its size. A diversity centre at the southern-edge population of M. kusanoi, and a contiguous range expansion from Kending, were found. These results indicate that the M. thunbergii populations at Tashueshan and Shiouhluan and the M. kusanoi population at Kending, and even Soukar, are evolutionarily significant units for conservation programmes. [source] Tool hoards and Neolithic use of the landscape in north-eastern IrelandOXFORD JOURNAL OF ARCHAEOLOGY, Issue 1 2004Douglas B. Bamforth Summary. Archaeologists frequently suggest that the Neolithic occupants of Ireland and Britain may not have been fully settled farmers, but were, instead, at least partially nomadic pastoralists. However, human use of any landscape is more complex than the current debate suggests, and this debate has included few systematic studies designed to evaluate this issue in detail. This paper examines hoards (or ,caches') of flaked stone tools in County Antrim, Ireland, to consider the links between anticipatory tool storage and human land-use patterns. Our data imply regular human movements over the study area, possibly linked to transhumant use of different altitudinal zones, with functionally and, sometimes, technologically specific classes of tools stored in different areas. However, the larger context of data on the Irish Neolithic clearly indicates that these movements were part of a way of life centred on permanent horticultural homesteads. [source] | ||||||||||